The invention relates to the connection between a flat bar and a flexible drive belt in the flat arrangement of a revolving flat card. Such a connection is shown in EP-A-627507 and in EP-A-753610 (or U.S. Pat. No. 5,956,811).
The belt according to EP-A-627507 comprises fastening elements provided in pairs which form a snap-in connection with the flat bar. EP-A-753610 shows a special drive belt for the flat bars of a revolving flat card, the belt provided with connecting elements which are formed integrally with a flexible belt and are arranged in pairs. One pair of elements in a flat bar part can be received to form a snap-in connection. Each element comprises a transverse beam with an inclined surface, with the inclined surfaces of a pair of beams being directed in mutually opposite longitudinal directions of the flexible belt.
An object of the invention disclosed in EP-A-753610 was to propose embodiments with which mutually contradictory requirements could be fulfilled. For instance, the flat bar may remain rigidly connected in a predetermined position with the drive belt during the operation of the flat bar arrangement, or alternatively the flat bar can be easily removable and re-attachable if required (e.g. during maintenance).
Another object of the mentioned inventions allowed for a connection which did not require any additional fastening elements. It was noticed, however, that the latter goal was unreachable due to the high demands made by spinning, and threatened the fulfillment of the aforementioned target requirements.
Various features and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned from the practice of the invention.
It is an object of the present invention to increase the operational reliability of a revolving flat arrangement with a snap-in connection between a drive belt and a flat bar as compared with the aforementioned art. Solutions to achieve this object are obtained from the combination according to the following claims.
The present invention includes a locking element that is incorporated into a drive belt assembly for a revolving flat card. A flexible belt of the drive assembly is provided with a pair of connecting elements formed integrally therewith. The connecting elements take the shape of a cross beam having an inclined surface. The locking element is disposed between the pair of connecting elements in order to prevent the connecting elements from approaching one another. Additionally, the locking element may be removed from the pair of connecting elements in order to allow the connecting elements to approach one another.
Alternatively, a pair of elastically deformable drive belts may be provide in a revolving flat unit, each having locking elements disposed thereon. A flat or a flat bar may be connected to the belt which has a connecting part that substantially prevents the divergence of the two holding elements of the drive belts.
The present invention also provides for a drive belt assembly as previously discussed which further has a head section with a locking bar that is disposed between two of the connecting elements to further lock the assembly into place.
The present arrangement is suitable for use with known flat bars with cuboid flat heads, and also with flat bars which are provided with bar-like slide pins, e.g. according to EP-A-567747.
Further advantages follow from the description below. The design is explained in closer detail on the basis of examples shown in the drawings. The explanation starts out from the embodiments according to EP-A-627507 and EP-A-753610, so that the latter solutions are explained first (as the xe2x80x9cinitial situationxe2x80x9d).